1. Technical Field
The present disclosure relates to an integrated magnetic sensor for detecting vertical magnetic fields and to the manufacturing process thereof. In particular, the disclosure relates to a Hall-effect sensor able to amplify the components of a magnetic field directed perpendicular to the sensor.
2. Description of the Related Art
As is known, the integration of a thin ferromagnetic layer in a standard CMOS process or a CMOS-compatible process enables producing integrated magnetic-field sensors, such as Fluxgate and Hall-effect sensors, which are able to detect horizontal magnetic fields.
An example of Hall-effect sensor 1 having a concentrator is shown in FIG. 1, wherein a substrate 2 of semiconductor material accommodates a pair of Hall cells 3. A concentrator 4 extends on the surface of the substrate 2, insulated therefrom via an insulation layer (not shown).
The concentrator 4 is formed by a strip of ferromagnetic material, the ends whereof are vertically aligned to a respective Hall cell 3, obtained in a known way and thus not shown in detail. Moreover this figure shows the lines of flux of an external magnetic field B oriented parallel to the surface of the substrate, as deviated by the concentrator so as to traverse the Hall cells 3 in a direction perpendicular to the surface of the substrate. Thus the external field may be detected by the Hall cells, which are in themselves sensitive only to the components of the field perpendicular to the surface.
In practice, the concentrator 4 causes an increase in the sensitivity of the sensor, thanks to the capacity of modifying the lines of flux of the magnetic field and concentrating them in the proximity of the Hall-effect sensors 3.